My husband is a master gardener and is an artist in the field of gardening to name one of HIS many talents!
We (oops I mean HE) grows a couple of beautiful hydrangea plants. At the end of the summer season, he will go around and pick the last of the flowers before the first frost. This hydrangea was clipped when it was still green. But as it dried in the vase it became this beautiful blue-ish green that is gorgeous. I still have it! (Of course the painting is while it was still fresh!)